Key Technical Points for the "Three Sheds and One Film" Cultivation of Greenhouse Grapes in Turpan

Key Technical Points for the "Three Sheds and One Film" Protected Grape Cultivation Technique in Turpan City

Turpan's climate is characterized by rapid temperature rise in spring, an early and relatively long summer, and a relatively slow temperature drop in autumn. Accordingly, protected grape production is mainly focused on early-forcing cultivation. Through 3 years of experimentation and demonstration work on protected fruit tree cultivation, the author has summarized the "three sheds and one film" technique for early-forcing cultivation of protected grapes. A brief introduction follows.

Large shed guides dormancy. The temperature conditions before entering dormancy are very important. Greenhouse cooling should begin 10 to 15 days before dormancy to enter the guided dormancy period. Turpan's climate in October to November is characterized by hot days and cool nights. Guided dormancy begins on October 20. During the day, cotton quilts are covered to prevent the grapes from receiving light; at night, the cotton quilts and ventilation openings are opened to let cold air into the shed. When covering with cotton quilts, cover 1/3 on the first day, 2/3 on the second day, and fully cover on the third day. When the temperature inside the shed drops to 0-7.2°C, cotton quilts are covered day and night to begin dormancy.

Practice has shown that grapes can complete dormancy with a dormancy-breaking agent as long as 40% of their normal dormancy hours are met. Therefore, it is not necessary to complete 800 to 1,500 hours of dormancy. Using the "three sheds and one film" technique for temperature rise and hydrogen cyanamide to break dormancy and promote early sprouting is one of the key techniques for early-forcing grape cultivation. From November 25 to December 10, the greenhouse temperature is raised. At this time, the cotton quilts are gradually opened: 1/3 opened on the first day, 2/3 opened on the second day, fully opened on the third day, and normal quilt opening and covering work begins on the fourth day. December in Turpan is relatively warm; the coldest period runs from the end of December to the end of January, and temperatures begin to rise in early February. The relatively low temperatures during the grape sprouting period have a significant impact on grape budbreak. The "three sheds and one film" technique can ensure the temperature needed for sprouting and new shoot growth. The three sheds are a medium shed and a small shed nested inside a large shed; the medium shed uses polyvinyl chloride film slightly thinner than the shed film. Within the medium shed, the grape vines are pulled down and laid in the furrow, and the small shed is then installed over them. The one film refers to laying plastic film on the ground to raise soil temperature.

The "three sheds and one film" technique has a good heat-preservation effect. According to measurements taken on January 10, 2014, the outdoor temperature outside the greenhouse was -12°C, the temperature inside the outer shed was 9.7°C, and the temperature inside the medium shed was 16.3°C, which was 6.6°C higher than a single-layer shed. The temperature inside the small shed was 21.5°C, which was 10.8°C higher than a single-layer shed. The soil temperature inside the small shed was 15.6°C, while the soil temperature outside the greenhouse was -8°C.

Hydrogen cyanamide has a good effect on breaking grape dormancy. Select a concentration of 15% to 20% according to tree vigor. Apply it when temperature rise begins. During the temperature rise period, special attention must be paid to heat preservation and temperature increase measures. 1) Add cold-proof barriers. 2) Improve wind and cold protection equipment for the side room and doorway. 3) Increase the cold-proof effect of the rear roof. 4) Enhance the cold-proof performance of the insulating quilts. 5) Plug the ventilation holes in the side walls. 6) Replace the shed film to enhance light transmission performance. 7) Lay plastic film on the ground to prevent moisture loss and increase soil temperature preservation. 8) Scientifically determine the rolling and unrolling times of the cold-proof quilts. 9) Promote the use of heat-generating fertilizers.